Various changes for a tabbed UI like Tower app.
Removed RepoTabView class.
Replaced not found app icon with default app icon.
Code clean-up
Created ace editor for diff view.
Changed ace editor diff view to pre and used custom renderingfor diff coloring.
Splitted file item elements in pistachio.
Removed ace editor which used to show diff.
Now using a custom pre element to show diff. No need to ace anymore.
Added KommitView.
Added StatusList.
Added new files to manifest.
Implemented status list and kommit view classes.
Merge pull request #1 from fatihacet/tower-ui

UI improvements